Effects of adrenomedullin on the cardiac performance and coronary flow in an isolated perfused rat heart model

Article type: Research Article

Authors: Amatyakul, Supatra^; | Patumraj, Suthiluk | Niimi, Hideyuki

Affiliations: Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand | Department of Vascular Physiology, National Cardiovascular Center Research Institute, Suita, Osaka 565‐8565, Japan

Note: [] Corresponding author. Fax: +66 2 252 7854; E‐mail: [email protected].

Abstract: The effect of adrenomedullin (AM) on the cardiac performance and coronary flow were studied in an isolated perfused rat heart model based on the modified Langendorff method. The heart rate (HR), electrocardiogram (ECG), left ventricular contraction (LVC) (dP/dt), and coronary flow (CF) were measured before and after the application of AM. The effect of AM on the coronary flow was examined in the model with and without endothelial degradation, using different inhibitors such as NG‐nitro‐L‐arginine, glibenclamide, and indomethacin. The present results indicated that AM increased HR and CF, but decreased LVC significantly, while it had no effect on ECG. The vasodilatory effect of AM was discussed in views of endothelial‐dependence due to nitric oxide and K+ channel activation.

Journal: Clinical Hemorheology and Microcirculation, vol. 23, no. 2,3,4, pp. 269-275, 2000